Such a circuit-breaker is disclosed in Document FR-89 00 215. In that known circuit-breaker, the metal arc-splitting plates are stacked in a plurality of mutually juxtaposed compartments. The electric arc is divided by electrodes at the input of each compartment, and is then split up on the metal plates inside each compartment under the action of magnetic fields.
Disposing the metal arc-splitting plates in this way increases the overall size of the interrupting chamber, whereas it is desirable to reduce the overall size thereof.
Moreover, in that known circuit-breaker, it is necessary to create separate magnetic fields for the various compartments, one field being required per compartment. Each magnetic field is created by conductors appropriately disposed at the input of a compartment. The conductors are folded bars. It has been observed that the force of the magnetic field created by that type of conductor remains insufficient to extinguish the electric arc effectively despite the fact that the arc is split up on the metal arc-splitting plates.
In that document, it is suggested that the folded-bar conductors could be replaced by electric coils. But, in practice, it is very difficult to insert such electric coils inside an interrupting chamber having the above-described disposition because of the distribution of the metal plates inside the compartments.